Method and apparatus for installation of an underground seal beneath a garbage dump

ABSTRACT

A method and apparatus for installing an underground seal beneath a garbage dump in a strip-like manner. The earth is worked in strips under the garbage dump by the front end of a driving shield. The earth is transported to the rear end of the driving shield, and is compressed at the rear end. A strip-like layer of a waterproof material is inserted, under the protection of a cover of the driving shield. A supply tunnel pipe is constructed and subsequently dismantled, comprised of individual tunnel pipe sections, under the protection of the cover while the driving shield is moved forward. The dismantled tunnel pipe sections of the tunnel pipe are used to erect an additional tunnel pipe which is laterally displaced in a direction toward the next strip-like layer opposite the first one tunnel pipe behind the driving shield. By stabilizing the dismantled pipe sections they need not be dragged along or transported out of the remaining tunnel pipe.

FIELD OF THE INVENTION

This invention relates to a method for the installation of anunderground seal beneath a garbage dump by means of a driving shieldforced under the garbage dump, and a device for carrying out the method.

DESCRIPTION OF PRIOR ART

A method of this type is the subject of European patent document No.EP-A 0,230,667. According to this method, two parallel trenches are dugalong opposite edges of the dump, the depth of the trenchescorresponding to the depth at which the dump is to be underrun. Adriving shield then is forced under the dump from one trench to theother, earth being worked at its front side. Earth is filled in at theback of the driving shield and a strip of a sealing layer is therebyinserted. A power supply to and from the driving shield is run via atunnel pipe which was erected during the underrunning of the garbagedump and which pipe is made up of individual tunnel pipe sections. Whenthe driving shield has reached the other trench, it is turned by 180°and runs under the dump in the direction of the first trench, whereby anadjacent strip of a sealing layer is inserted and, at the same time, thepreviously assembled tunnel pipe is dismantled. After the first trenchis reached, the driving shield is again turned by 180° and runs underthe dump, as described above, in direction of the second trench wherebya tunnel pipe is laid anew.

A disadvantage of that method is that when the tunnel pipe is dismantledas the driving shield proceeds from the second trench to the first, thedismantled tunnel pipe sections must either be dragged along by thedriving shield or transported via the remaining piece of tunnel pipe.

SUMMARY OF THE INVENTION

An object of the present invention is to improve the method in such away that dismantling the tunnel pipe does not cause the aforenoteddisadvantage.

The object is attained in accordance with the invention in which anembodiment is a method for installing an underground seal beneath agarbage dump in a strip-like manner, progressively working the earth instrips under the garbage dump with the front end of a driving shield,transporting the earth to the rear end of the driving shield,compressing the earth at said rear end, inserting a strip-like layer ofa waterproof material under the protection of a cover of the drivingshield, constructing and subsequently dismantling a supply tunnel pipecomprised of individual tunnel pipe sections under the protection of thecover while the driving shield is moved forward, and using thedismantled tunnel pipe sections of the one tunnel pipe to erect anadditional tunnel pipe which is laterally displaced in direction towardthe next strip-like layer opposite said one tunnel pipe behind thedriving shield.

Another embodiment is an apparatus for installing an underground sealbeneath a garbage dump comprising a driving shield for progressivelyworking the earth under the garbage dump in adjacent strips includingapparatus for transporting the worked earth to the rear end of thedriving shield, apparatus for compressing the transported earth at saidrear end, a cover for the driving shield, apparatus for laying astrip-like layer of a waterproof material under the protection of thecover prior to disposing worked earth thereover, a first tunnel pipecomprised of individual pipe sections located beside the driving shield,and means for dismantling the pipe sections progressively andconstructing an additional pipe, using the dismantled pipe, laterallydisplaced from the first tunnel pipe behind the first tunnel pipe.

BRIEF INTRODUCTION TO THE DRAWINGS

Embodiments of the invention are described in greater detail below, withreference to the drawings, in which:

FIG. 1 illustrates a vertical section through a garbage dump and anembodiment of the device of the invention;

FIG. 2 illustrates a horizontal section through the garbage dump and thedevice of the invention; and

FIG. 3 is a further section along the line III--III of FIG. 2.

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

A tunnel pipe is laid at the foot of the dump in a trench along which,at the side facing dump, a feed press moves. The feed press picks up theearth at the front and compresses it at the back. A waterproof layer iscontinuously inserted as strips at the back of the feed press pipesections of the tunnel pipe are continuously dismantled as the pressadvances, and after having been laterally displaced, are assembled againto form a new tunnel pipe. The driving shield can have a foil roll whichunwinds continuously due to the feed motion of the shield in such a waythat the foil comes to rest underneath the dump. Also continuously withthe feed motion, the foil is welded with the edge of the previously laidfoil. The device is turned by 180° at the end of the dump, so that itcan insert and weld the next foil sheet in the same manner beneath thedump.

At least some of the Pipe sections of the tunnel pipe have inclined endprofiles, to make it possible to bend the tunnel pipe by radiallyturning it. In this way, a sealing underlayer can be inserted under thedump forming a tublike structure once the edges of the underlayer arepulled up to the surface of the earth.

A personnel and/or material pressure sluice, as well as an inflow funnelfor mineral sealing materials, which can be inserted above and below thefoil, can be disposed at each end of the tunnel pipe. The power supplyfor the conveyors and the driving shield follow along the tunnel pipe.

In order to prevent ground water from possibly entering the partiallyopen driving shield, the tunnel pipe can be filled with compressed air.Ventilation takes place via pressure pipes.

The driving shield is comprised of a base plate and a cover overlappingit, which are connected with hydraulic cylinders. The hydrauliccylinders are moved more or less quickly when the driving shieldadvances into the ground in order to reduce the top pressure. Ahorizontal feed press is located at the back end above the unwindingfoil, the earth worked in front of the driving shield being filled andcompressed behind the open top of the feed press. The shield of the rearfeed press is duplicated, so that filter material (gravel) to be placedon the foil surface can be inserted. The gravel is conveyed in throughthe rear tunnel pipe. Loam to be placed below the foil is conveyed inalong the front tunnel pipe. Rerouting of these materials from theconveyer belt to the installation sites takes place via pipes, baffles,etc.

The cover and base plate of the driving shield have movable bladeshields at the front and back ends, which enable a horizontal control.Vertical control is effected by loading the horizontal feed press and ahydraulic cylinder, which is supported on the rear tunnel pipe, in anappropriately different manner.

A further feature of the method is that the individual tunnel pipesections have a horizontal separation joint, so that the element halvescan be conveyed along the tunnel pipe and be installed or disassembledin the driving shield when displaced longitudinally.

The individual tunnel pipe sections can be connected to one another soas to be watertight by means of automatically operated hydraulicquick-action vises.

The driving shield, comprised of a cover plate 2 and a bottom plate 3,which are connected to one another via vertical hydraulic cylinders 5,is located beneath the dump 1. Blade shields 4a, 4b, 4c and 4d, pinnedto plates 2 and 3 so as to be rotatable about a horizontal axis, aredisposed at the front and back of plates 2 and 3 respectively. A rearfeed press 6 has an upper, horizontally hinged plate 7. Plate 7 isoperated by a hydraulic cylinder 8. Forward thrust is provided by meansof press 6 upon operation of operating hydraulic cylinder 9. Roll offoil 10 turns in direction of arrow 11, so that the unrolled foil 12comes to lie below the dump 1. At 13, foil sheet 12 is welded orotherwise adhered together with foil sheet 14, which was laid in aprevious step. The driving shield moves in the direction of arrow 15.

On conveyor belt 16, drainage filter material (gravel) to be placed ontop of the foil is brought in through the rear tunnel pipe, and loam 17to be placed below the foil is brought in through the front tunnel pipe.The loam as well as the gravel is inserted, in each case, via a funnel18 onto the conveyor belt in the tunnel pipes. The personnel sluice 19at the end and beginning of the tunnel pipes seals these hermetically.The tunnel pipe sections 20 are alternately diagonally separated andconnected via hydraulic quick-action vises 22. A clearing device 23works the earth. The worked material is transported along the directionof arrow 24 behind the rear feed press 6 and its plate 7.

The tunnel pipe section 25 is moved along the direction of arrow 26 tothe right and is connected there with tunnel pipe section 28 by means ofhydraulic clamping devices 22. 25' represents a displaced ring 25.Hydraulic cylinder 27 is retained on ring 28. Reference numeral 29designates the horizontal dividing lines of the piPe sections forseparating them into two half shells. Reference numeral 29' designatesthe displacement of dividing line 29 in order to attain a bend of thetunnel pipe shown in FIG. 1. Reference numeral 30 represents the foilwelding device.

The method is carried out as follows.

First of all, a tunnel pipe, consisting of the tunnel pipe sections 20,is laid along the dump in a trench, for example, the tunnel pipe at theupper portion of FIG. 2. The driving shield is then attached to thistunnel pipe, pointing in the direction of the dump, and a part of thefoil 12 is thereby pulled off roll 10. Gravel is applied to this part ofthe foil 12.

The earth beside the tunnel pipe is then worked by a clearing device 23.For this purpose, the clearing device 23 can be moved horizontally andvertically between the plates 2 and 3. The worked earth reaches plate 7via a conveyer belt in the direction of arrow 24 and onto the gravellayer disposed on the foil 12 behind press 6.

At the front end of the base plate 3, a loam layer 17 is inserted at thebottom in place of the earth which has been removed from there. Cylinder8 is then actuated, as a result of which plate 7 swings upwardly, aswell as the cylinders 9 of press 6, as a result of which plate 7 andpress 6 pack the ground behind the device and whereby the driving shieldis shifted in direction of arrow 15. Additional foil 12 is therebyunwound from roll 10.

The last tunnel pipe section 20 between plates 2, 3 is then moved indirection of arrow 26 to form a further tunnel pipe, the tunnel pipeshown at the lower portion of FIG. 2.

This procedure now repeats itself, i.e. applying gravel onto theadditionally unwound foil 12, working the earth beside the one tunnelpipe in front of the driving shield, transporting this earth behind thedriving shield beside the further tunnel pipe, inserting the loam layerin front of the driving shield and beside the one tunnel pipe,compressing the worked earth behind the driving shield beside thefurther tunnel pipe while simultaneously advancing the driving shieldand dismantling the last tunnel pipe section from the one tunnel pipeand attaching it to the next tunnel pipe.

In this way, a tunnel pipe is continuously dismantled and another tunnelpipe is, at the same time, built. A loam layer is inserted, a foil layeris laid on the loam layer when this other tunnel pipe is dismantled andthe next tunnel pipe is laid, gravel is applied to the foil layer andthe worked earth is packed over the gravel layer.

When the worked earth is packed behind the driving shield, the drivingshield can pull itself forward on the one tunnel pipe by means ofhydraulic drives and maintain itself on the other tunnel pipe by meansof hydraulic cylinder 27, which improves the feed motion in direction ofarrow 15.

The gravel can be delivered via the one tunnel pipe, whereas the loam isdelivered via the other tunnel pipe. Cleared earth can also be removedvia one of the two tunnel pipes, which is necessary when the clearedearth cannot be adequately compressed behind the driving shield.

A piping system for drawing off seepage water can be laid together withthe gravel layer on foil 12. This piping system is connected to apumping station and a treatment station, whereby seepage water ischemically treated in the treatment station. It is then again conductedto the surface of the dump in order to wash out destructive materials.

Since each of the tunnel pipe sections 20 has a front side 21 whichextends alternatively vertically or diagonally to the pipe axis, it ispossible to bend the tunnel Pipe by turning the tunnel pipe ring 20about its axis, as is shown on the right side in FIG. 1.

The cover 2 of the driving shield is preferably distinctly larger thanthe base plate 3. In order to prevent the earth from falling in on theside, the driving shield has laterally movable shields 31.

I claim:
 1. A method for installing an underground seal beneath agarbage dump in a strip-like manner, comprising progressively workingthe earth in strips under the garbage dump at the front end of a drivingshield, transporting the earth to the rear end of the driving shield,compressing the earth at said rear end, inserting a strip-like layer ofa waterproof material under the protection of a cover of the drivingshield, constructing and subsequently dismantling a supply tunnel pipecomprised of individual tunnel pipe sections under the protection ofsaid cover while the driving shield is moved forward, and using thedismantled tunnel pipe sections of the one tunnel pipe to erect anadditional tunnel pipe which is laterally displaced in direction towardthe next strip-like layer opposite said one tunnel pipe behind thedriving shield.
 2. A method according to claim 1, including pulling thedriving shield forward on said one tunnel pipe via hydraulic driveswhile supporting itself on said additional tunnel pipe,
 3. A methodaccording to claim 2, including unwinding a foil strip beside saidadditional tunnel pipe under the protection of the cover by the forwardmotion of the driving shield, and welding or bonding the foil with foilsheet already laid in a previous step.
 4. A method according to claim 3,including inserting said waterproof layer beside said one tunnel pipeand in front of the driving shield, said layer being run over by thebase plate of the driving shield.
 5. A method according to claim 4,including conveying excess waste material and sealing material to beinserted in the tunnel pipes.
 6. A method according to claim 5,including attaching personnel and/or material sluices at the ends of thetunnel pipes.
 7. A method according to claim 6, including laying pipingon the layer of the waterproof material for drawing off seepage water toa pumping station and treatment station.
 8. Apparatus for installing anunderground seal beneath a garbage dump comprising a driving shield forprogressively working the earth under the garbage dump in adjacentstrips including means for transporting the worked earth to the rear endof the driving shield, means for compressing the transported earth atsaid rear end, a cover for the driving shield, means for laying astrip-like layer of a waterproof material under the protection of thecover prior to disposing worked earth takeover, and a first tunnel pipecomprised of individual pipe sections located beside the driving shield,and means for dismantling the pipe sections progressively andconstructing an additional pipe, using the dismantled pipe, laterallydisplaced from the first tunnel pipe behind the first tunnel pipe. 9.Apparatus as defined in claim 8 including means for pulling the drivingshield forward on said one tunnel pipe via hydraulic drives and forsupporting itself on said additional tunnel pipe.
 10. Apparatus asdefined in claim 9 including means for unwinding a roll of foil stripbeside said additional tunnel pipe under protection of said cover as thedriving shield moves forward.
 11. Apparatus as defined in claim 10including means for transporting sealing material within said tunnelpipes.
 12. Apparatus as defined in claim 11 including personnel and/ormaterial sluices at the ends of the tunnel pipes.
 13. Apparatus asdefined in claim 11 including drainage pipes for drawing off seepagewater disposed on the layer of waterproof material.
 14. Apparatus asdefined in any one of claims 8-13 in which at least some of the tunnelpipe sections have end profiles extending alternately vertically anddiagonally to the pipe axis, in such a way that a bend of the tunnelpipe results when the tunnel pipe sections are turned about their axes.15. Apparatus as defined in any one of claims 8-13, and furtherincluding a clearing device for working the earth beside said one tunnelpipe and in front of the next tunnel pipe.
 16. Apparatus as defined inclaim 8, and further including a clearing device for working the earthbeside said one tunnel pipe and in front of the next tunnel pipe, inwhich said cover is larger than the base plate.
 17. Apparatus as definedin claim 16, further including laterally movable shields for preventinga cave-in.
 18. Apparatus as defined in any one of claims 10-15, furthercomprising a substantially vertical press located at the rear end of thedriving shield above said roll of said foil strip having a foldingplate, for backfilling and compressing earth behind the driving shield.19. Apparatus as defined in claim 18, in which the substantiallyvertical press has a duplicate spaced wall for guiding drainage filtermaterial to the surface of the unwound foil strip.